


Where the Sea Meets the Sky

by janonny



Category: Marvel Cinematic Universe
Genre: And this is a shipfic, Comedy, Crack Treated Seriously, Fluff and Humor, Happy Ending, Little Mermaid Elements, M/M, Trust me in shippiness, Warning: There is mention of gruesomeness but no details, and it's a passing mention, merman, that doesn't involve any of the main characters
Language: English
Status: Completed
Published: 2019-12-25
Updated: 2019-12-25
Packaged: 2021-02-26 01:09:01
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 17,971
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21954913
Author URL: https://archiveofourown.org/users/janonny/pseuds/janonny
Summary: Steve is recuperating in a seaside town when he meets a merman. Or rather, a merman finds him and asks —demands, really — to be taken home with him to learn about the human world. And that isn’t even the strangest part...-“I don’t know what the whole immortal soul and seafoam bits were about. Why would we turn into seafoam? It shows a real lack of understanding about biology, science and magic.”
Relationships: Steve Rogers/Tony Stark
Comments: 72
Kudos: 439





	Where the Sea Meets the Sky

**Author's Note:**

  * For [This_Is_Captain_Handsome](https://archiveofourown.org/users/This_Is_Captain_Handsome/gifts).



> This story is a Christmas gift, dedicated to [This_Is_Captain_Handsome](https://this-is-captain-handsome.tumblr.com/) (because of all your wonderful merman art and hilarious ideas!).
> 
> I did run out of time, so even though I’ve edited it a couple times, it’s still sadly not beta read yet. I hope you enjoy it anyway!
> 
> For all readers, if you spot any typos, spelling or grammatical mistakes, please feel free to point it out (in comments or Discord or any way you know how to reach me). But only if you feel like it of course. I’ll have this beta read at a later stage and replace this with the beta-ed version at some point. Thank you for reading!

The day started like any other day. 

Steve had gone for his morning run, pushing hard for miles around town and along the beach until he was finally out of breath. After that, he lay back against his usual slab of rock, letting his hand fall into a rockpool and graze against the moss-covered rocks. It had been high tide in the morning but the water had receded now, leaving behind beautiful, emerald pools of water among the rocks. He closed his eyes, tried to calm and center his mind. He liked to spend at least 20 minutes just stretched out by the beach, absorbing as much sunlight as he could. 

His therapist had said that it was important to have a routine. Not that he had followed much of his therapist’s advice, otherwise he wouldn’t be out here in this quiet town on his own. But he liked the idea of a morning routine so he stuck to one.

He listened to the sound of the waves and enjoyed the warmth of sunlight against his skin, just like any other morning.

Except unlike other mornings, something woke him from his usual warm drowse on the rocks. A light touch brushed against his cheek. He leaned away from it and cracked open an eye, expecting to see a crab scuttling away. 

It wasn’t a crab. 

He turned his head fully, mouth falling open as he stared in wordless shock. 

Half submerged in the rockpool, upper body pushed out from the seawater and leaning against the warm rocks, was a person. 

A very, very small person. 

Small enough to fit on the palm of Steve’s hand. 

Steve’s mind just couldn’t comprehend what he was seeing. His jaw worked as he took in the dark hair swept back from the little face, so much like a doll’s, with large brown eyes and a neat little goatee, framing a small but plush mouth. The little being was frowning, head tilted. On his bare chest, was a tiny circle of illegible scribblings, glowing faintly blue.

There was a small splash in the water and Steve found himself even more astonished when the little being propelled himself out of the water to reveal that the lower half of his body wasn’t legs, but a fish tail with vibrant red scales that shone with a golden glimmer in the sun. The little...half-fish-person flopped onto the rock and waved at him, gestured incomprehensibly with a small hand. 

“I’m hallucinating,” Steve wondered aloud. “Maybe it’s a heat stroke.” Never mind that it wasn’t possible for him to get heat stroke. 

The half-fish-person rolled his eyes, which didn’t seem like something a hallucination should do. It just looked so normal on a strange being like that. Steve finally figured out that the being was gesturing at Steve’s hand, like he wanted them to shake hands or something. 

Although all common sense said he shouldn’t be touching unknown small alien creatures, Steve was also half-convinced that this was all a hallucination. 

It didn’t help that he couldn’t seem to stop thinking, ‘Gosh, he’s so cute’ over and over again, which probably meant his common sense was at an all time low at this point. But the little half-fish-person really was incredibly cute, with his small frowning face and his tiny hands. 

So without much further thought, Steve tentatively stuck out his index finger towards the small being. 

Tiny hands gripped the tip of his finger. 

_“That took you long enough, I was patting your cheek for almost half a minute before you woke up, sleeping beauty.”_

Steve yanked back his hand. 

That voice...it hadn’t been speaking aloud. That smooth voice had been in his head. What the hell? Steve stared wildly at the little face that looked affronted at Steve’s reaction. For some reason, a tiny merman was shocking but _telepathy_ was just a step too far. Steve felt like he had lost his mind. 

The merman sat sideways, propped up by one hand with his tail to balance him. He gestured imperiously with his free hand again. 

If Steve really was crazy, did it matter if he indulged in his own delusions? He reached out a finger again, a little uncertainly.

_“I figured you two-legs wouldn’t be able to mind-talk but I didn’t think you would react so badly. I’ve read some of your stories, the concept has come up in your fiction.”_

“You mean...like telepathy in science fiction?” Steve asked, wondering what other strange things his hallucination was going to say next.

The creature nodded before frowning. _“Somewhat but not exactly. Telepathy in your stories usually involves mind-reading. I can’t read your mind, I’m just projecting my words into your mind. It’s how my kind talks. If you were in the water too, we wouldn’t need to touch to communicate this way.”_

Steve wasn’t an uncreative person. He drew a lot and wasn’t short on imagination when he was a child. But even so, he didn’t think this was something that his brain would come up with, even in the throes of madness. He admitted, a little dazed, “I have no idea what’s happening.”

Sighing, the creature said into Steve’s mind, _“Have you heard of The Little Mermaid?”_

# # # # # # 

So apparently, The Little Mermaid wasn’t so much a Disney fairytale as it was a biography, with great liberties taken. For one thing, the _Little_ part of The Little Mermaid was a lot more literal than the original story and subsequent remakes portrayed. 

_“I don’t know why Hans Christian Andersen thought people would be open to the idea of mermaids but not_ **_little_ ** _versions of them. Not that we’re actually little, it’s just that your kind is huge so we seem little in contrast.”_

Steve only had a vague idea that many of the fairytales consumed by the general public were vastly changed from the originals told by the likes of Hans Christian Andersen and the Brothers Grimm but he hadn’t actually known The Little Mermaid was one of them. He listened on in somewhat of a daze. 

The little mer...man in front of him was an entertaining storyteller, but had a tendency to tangent off. There were comments like: 

_“If you think about it, why would a half-woman, half-fish be the same size as your people? Most fish aren’t so very large.”_

Or:

_“I don’t know what the whole immortal soul and seafoam bits were about. Why would we turn into seafoam? It shows a real lack of understanding about biology, science and magic.”_

At the end of it, what Steve got out of the explanation was that The Little Mermaid was a true story, except vastly changed. The mermaid, called Macy, not Disney’s Ariel apparently, had been very small and had allowed herself to be discovered by a prince because she was so curious about humans, otherwise known as two-legs to merpeople. The whole mute part of the story was apparently because the merpeople didn’t communicate by audible speech. The prince and Macy fell in love and they both decided to be together in the sea. 

“Wait, what?” Steve interjected. “How? There’s the whole size difference and he’s human? And I thought she ended up staying on land instead?”

 _“In Andersen’s story, she doesn’t end up with the prince and she thought she was going to die but that was just Andersen loving his melodramatic endings.”_ The merman flipped his pretty long fins on his tail dismissively. _“Anyway, they used magic, of course, to turn the prince into a little merman.”_

Steve blinked, mouth falling open again before he shook his head. “Of course… Magic. Of course.”

_“Yes, magic, it’s all very boring. Magic is a very boring and limited tool. Andersen got the core principle of magic correct at least. Everything done by magic comes at a price. There has to be an equal exchange.”_

“What was the price for turning the prince into a little merman?” Steve asked with a frown, swept up by the story despite the information overload and his sense of disbelief. 

The merman pointed at Steve’s legs and then made a chopping motion. _“Pain and blood always makes for a good exchange. There was also the risk of death from massive blood loss but the magic worked pretty fast.”_

Steve grimaced at that. Yeah, that seemed to be a pretty big gruesome price. He tried to move on from that back to the original point. “So...what does that have to do with why you’re here?”

 _“Eric, the prince, told Andersen his story which Andersen took liberties to. Macy told our people stories about the two-legs’ world, which was passed down over the generations. I’ve gleaned more from eavesdropping on ships and two-legs on the beach, and from exchanging information. But I’ve reached the limit of what I can learn about your world from the sea, so I’ve decided to come spend time living with a two-leg on land,”_ the merman explained, almost matter-of-fact. 

“But...what? You just decided like that? Wait, living _with_ a two-leg?” Steve realized what this meant. “You’re talking about me. You don’t even know me. I don’t even know your name.”

 _“I’m Tony Stark and your name is Steve,”_ Tony said, and started checking off his fingers. _“You come to the beach every morning where you run gracefully but repetitively up and down until you lie down on this rock. You’re polite but you’re not good friends with the rare person you see here. You’re a strong swimmer and you’re kind because I watched you save Wade from that horrible kid once and because you throw starfishes back into the sea when you find one.”_

Wade must have been that crab Steve had rescued from a boy that had been talking about pulling off his legs. That was the only time Steve had saved anything from anyone on this beach. 

“You’ve been watching me,” Steve said, not sure to be disturbed or not. 

_“I’ve been watching the beach, you just happen to be on the beach.”_ Tony’s tone sounded offended. Then he clung on tighter to Steve’s finger and turned wide eyes up at Steve. _“Please, Steve, I won’t take up much room at all. There’s so much I’m dying to learn, I just need a chance.”_

Oh god, the big puppy eyes on that little face was just too cute. Those tiny little lashes that rimmed the deep wide eyes was just too much. Steve tried to stay strong, tried to be rational, rubbing his forehead as he stalled. “I don’t know… This is a lot to take in.”

 _“Aren’t you at all curious about my people? Don’t you want to learn about us in turn?”_ Tony asked, blinking slowly as if he had figured out Steve’s weakness. 

And damnit, but Steve did want to learn about Tony’s kind. This was the most interesting thing that happened to him during his extended holiday. Tony must have read the softening of Steve’s resolve on his face because he flung his hands up in the air in clear excitement. Of course, that cut off their contact so Steve couldn’t hear whatever Tony might be saying. Tony quickly grabbed Steve’s finger again, grinning. 

_“Thank you, you won’t regret this,”_ he enthused. _“Now, please fish out the plastic bag I towed over with me. Two-leg’s trash in our sea is disgusting but at least this one can be useful while we remove it from the water. I’ve already filled it up with seawater for the trip back to your place. I can stay out of water for a few hours but it’s presumably easier to carry me like this on land. Be careful with the bag, there are a few pearls in it to help pay for my stay with you,”_ Tony explained in a long ramble as he grinned and pointed into the rockpool. 

It seemed his verbal agreement wasn’t needed in the face of Tony’s enthusiasm.

Steve fished out the plastic bag indicated, which was a see-through plastic about twice Tony’s size. At the bottom of the bag, there lay five large pearls, lustrous white and perfectly round, each larger than Steve’s thumb. Tony was absurdly trusting to show this to the first human he talked to.

Steve shook his head and said, “You don’t have to pay me in pearls, I’m sure you’re not going to cost me this much.”

 _“I’m a Stark, we pay for where we stay. And the pearls will pay for other things I’ll be needing too,”_ Tony said with a shrug. 

That sounded almost ominous. What would Tony be needing?

# # # # # #

Even though Tony was riding in the plastic bag, Steve could practically feel his excitement thrumming through when they reached his house. It was located only ten minutes away on foot from the beach but Steve had kept one hand cradled around the plastic bag for the entire trip, to try to block his little strange parcel from sight even though he didn’t see anyone on his way back. 

The moment Steve opened his front door, Tony popped the top half of his body out of the bag, leaning precariously on the plastic’s edge, and grabbed hold of Steve’s thumb. 

_“Hold me up, I want to see,”_ Tony demanded. _“What’s that? And that? Take me around and tell me what everything is.”_

That was how Steve ended up walking through the small two bedroom house, naming all kinds of mundane household items so Tony could learn what they were. It took an hour and a half before Tony was satisfied. 

“What’s next, your majesty?” Steve asked sardonically. His initial awe and surprise was fading after being bossed around so thoroughly by a little merman less than six inches tall. If this was a hallucination, he had to give credit to his imagination for being so wild and unusual. 

Tony tapped on the faintly glowing circle on his chest while he said thoughtfully, _“I need a stable container for my seawater and your phone please.”_

“My phone?” Steve asked, a little baffled. 

_“How else will I learn more?”_ Tony pointed out pragmatically. _“You’ve explained as much as you can but we’re probably reaching your technical limits. So about that container?”_

Thinking about Maria, who kept tropical fish and had once vented about irresponsible fish owners who put fish in too small tanks, Steve made his way to his bathroom. There was a bathtub in there which was spacious enough for him, so surely it was big enough for Tony. 

“I could fill out the tub so that it’s full and prop my phone on the edge of the tub?” Steve offered. 

Tony swam about in his little plastic bag, trying to look at the bathroom from every angle. He popped back up and grabbed Steve’s thumb where he was holding the edge of the bag. _“Where will you sit?”_

Steve frowned. “Um, well, I usually do some drawing at this time of the day and I sit in the living room.”

 _“Then I want to be in the living room too. What if I want to talk to you? I can’t do it from all the way in here,”_ Tony pointed out. 

“Oh, then I can bring my sketchpad in here instead and sit by the bathtub.”

But Tony was already shaking his head, body half hanging out of the plastic bag to stare at the space beside the bathtub. _“That looks so uncomfortable and I can’t imagine how you would be able to draw properly in that position. Let’s go back out_ — _Woah!”_

Fortunately, Steve’s other hand was already hovering beneath Tony, predicting the accident from the way Tony couldn’t keep still. The top quarter of the plastic bag folded over and Tony tipped out straight onto Steve’s hand. Tony wriggled around until he flopped onto his back, blinking up at Steve as he leaned back against Steve’s fingers, his bright fins draped over his wrist. 

It was definitely a strange feeling; the wet scales against his skin, the little body resting in his palm. 

Tony recovered quickly, sitting up and gripping Steve’s thumb. _“Thank you. Now let’s go outside. I think your kitchen should have something suitable.”_

That was how Steve ended up with a clear glass on his desk with a little merman examining it from the outside. “I didn’t bring any seawater with me,” Steve said a little fretfully, realizing suddenly that Tony might not be able to cope with water from the tap, not when he came from the sea. 

_“Don’t worry, Sorcerer Strange magicked the plastic bag for me. It’s linked to the sea so it pours seawater,”_ Tony said from where he had been placed beside the glass. He had pulled himself up by the lip of the glass and was looking up at Steve. 

Steve blinked and tipped the water in the plastic bag into the glass. The glass filled up quickly but when he straightened the plastic bag, the water level didn’t look like it had dipped at all. And at the bottom, remained the five pearls. 

But Tony wasn’t paying attention to the glass or the plastic bag or even Steve anymore. He was lying flat on his front, flashy tail waving in the air behind him as he tapped on Steve’s phone with his palms. Steve raised his eyebrows at how Tony worked the phone with confidence, when Steve was pretty sure that this was the first time Tony had ever used one. He seemed to be mostly using Google. 

Steve settled down on the desk, spending long minutes staring at the little wonder in front of him, and sketching Tony while he worked. Every hour or so, Tony pulled himself up and over into the glass of seawater, swirled around inside in dizzying impatience before plopping back out again so he could use the phone, leaving little puddles of water behind him. 

Within an hour, Tony was using the phone in ways that Steve never even imagined was possible. 

Within two hours, Tony presented him with a shopping list and a pearl, declaring every purchase on the list as critical. 

# # # # # #

Over the next couple days, Steve had let go of the idea that this was a hallucination. It was too strange to be a hallucination. 

It was clear from the onset that Tony was here to learn as much as he could. He was endlessly curious and voracious in his reading. He studied on his tablet — his own, which Steve had bought and had cost quite a lot — with as much enthusiasm as he did watching television with Steve at night, sitting in his glass on the coffee table. 

Tony spent a lot of time pouring over his tablet, concentrating with a little frown on his face and sometimes worrying at his lower lip in thought. He wore the same expression when he was watching television and came across some human social etiquette that was just beyond his understanding. Applied to both wildly different scenarios, that expression was just so _serious_ which somehow made it even more adorable. 

Tony had also installed all kinds of apps on Steve’s phone before he started using his own tablet, so some days, Steve just sat by Tony as he worked and played a bunch of oddly addictive mobile games. Sometimes, Tony would even find a game where the two of them could play together on their phone and tablet respectively. There was a game called ‘Sea Garbage Party’ which, despite the unpleasant name, was very cute and fun with all kinds of puzzles and speed challenges, along with animated graphics consisting of strange garbage one can find in the sea. 

When Steve wasn’t playing silly games on his phone, he was also drawing Tony a lot. Tony was the most interesting sight in the whole house, possibly the whole planet, and he could be so unbearably cute sometimes, it was impossible for Steve to resist putting pencil to paper with the little merman as his muse.

On day four, Tony decided he needed to be more hands on. He had demanded to see Steve’s toolbox which meant Steve had to go out and buy one since he didn’t actually have a toolbox in this house. Tony had examined each tool closely, most of them larger than he was. He had flopped and tumbled over the tools, and Steve had to rescue him when it looked like he was going to accidentally stab himself through his stomach with a screwdriver after he tried to lift it by its pointy end. And all Steve got for as thanks was that serious frown, as if Steve was impeding Tony’s learning process by stopping him from stabbing himself. 

Tony was sheer determination squeezed into all of six inches and he wasn’t going to let something like a body not compatible to dry land or human-sized tools stop him.

He often had to wriggle over the surface of the table or the tablet so he could use it properly. His bright tail tried to propel him forward by flapping through the air, satin-like tail fins trailing behind him as he moved with much less grace outside of water. None of that ever slowed him down. Tony didn’t let anything like inelegance affect what he did. 

Sometimes, Steve had to remind him to get back into the water, right now, when he forgot how long he was out and his scales had started to dry out. Tony always grumbled but he still hopped into his glass, swishing around in frantic circles like that would speed up his body soaking up the seawater again. 

Seeing Tony’s impatience, Steve finally came up with an idea that could help. 

Tony watched with interest from his glass as Steve set up an aquarium in the middle of the living room, with a new stand he had bought just for it. 

“It’ll take awhile before the aquarium will be usable, maybe about four to six weeks. There’s all these things about cycling the tank and curing the live rock. So you won’t be able to use it right away,” Steve explained. He moved over to his desk from the large tank so that he could touch a finger to Tony’s outstretched hand. 

_“It seems like it’ll be too much effort to move to and from the tank and the table with the tablet,”_ Tony said with tentative uncertainty. 

Steve smiled. Of course Tony wouldn’t want his research time to be taken up by any travelling time. “It’s why I’ve ordered an Alltab. It’s a tablet that works under water.”

 _“Oh! Why didn’t I think of that?”_ Tony sounded genuinely surprised that he wasn’t somehow able to consider every possible type of technology a week into his research on human tech.

“That’s what I’m here for, to help you learn more about us ‘two-legs’ and our world. Not that I’ve been of much use up to now,” Steve said with a self-deprecating smile. He was well-aware that Tony didn’t really need him, was learning everything he needed from the Internet.

Tony frowned. _“Don’t be ridiculous, all this would be impossible without you. And this tank… It will cost you quite a lot, won’t it? And you never took a pearl to sell.”_

Ah, Steve wondered if Tony had noticed that. After all, the little plastic bag of seawater was usually tied up and stowed away in the kitchen, only taken out in the mornings for a fresh glass of seawater. Tony never seemed to pay any attention to the pearls at the bottom of the bag. 

“It’s expensive but I can afford it,” Steve said with a shrug. 

_“The pearls are meant for my necessities. You really should sell them and use the money instead,”_ Tony urged. 

Steve frowned and explained, “They look like really nice pearls. You should keep them instead or save them for when you really need to use them.”

For a brief moment, Tony was just silent, staring up at Steve contemplatively. Then he said, _“Put your hand out please.”_

Steve was a little confused since Tony was already touching his finger but he extended his other hand so that it was level with the glass. Tony hauled himself out of his glass and flopped onto Steve’s outstretched hand. _“Lift me up please.”_

Obediently, Steve lifted Tony up, higher and higher based on Tony’s impatient gestures. When Tony was on eye level with Steve’s face, he said, _“Closer please.”_

Now a little uncertain, Steve drew Tony closer and closer, until he couldn’t quite focus on Tony. Then suddenly, Tony shifted to the side, almost falling off Steve’s hand altogether. Before Steve could panic, he felt little hands touched his cheekbone, touched his cheek, and then the softest of small touches brushed against his cheek. 

It took a moment for Steve to register that Tony had just kissed him on the cheek. 

Tony, all of six inches high, had kissed him on the cheek. 

Steve knew he was blushing, flushed to a ridiculous degree when he drew Tony back so he could look at him again. 

_“Thank you, Steve.”_ Then Tony examined Steve’s flushed face. _“You’re blushing. Why are you blushing? That’s how two-legs say thank you, right?”_

“Um...not always. It can also be a sign of affection,” Steve explained, trying not to stutter. 

_“Well, that’s alright then. I feel quite a lot of affection for you.”_ With that casual statement, Tony pointed to the desk. _“Okay, I want to get on to reading about nuclear energy, please put me down again.”_

And that apparently was that. 

Except Tony started incorporating cheek kisses into their daily routine as a necessary show of affection and gratitude, according to Tony.

Steve never stopped blushing when he got a cheek kiss and Tony never stopped looking disproportionately smug and amused at that.

# # # # # #

Steve was out for his jog one day when he received a text message on his phone. He slowed down and took his phone out, checking what it said. 

_\- Buy chocolate, I want to try it_

_\- This is Tony by the way_

Grinning, Steve shook his head. He should have known that it wouldn’t be long before Tony mustered text messaging so he could communicate with Steve no matter what. 

_\- Also a cheeseburger please_

_\- And pizza_

_\- And blueberries_

Okay, looked like today would be a day of food tasting. Tony was capable of eating human food, they had already tried it out before. But he had seemed content to eat whatever Steve was having, which was mostly rice and pasta. It seemed Tony was ready to branch out. 

Later, Steve had to hide a smile while Tony lay on his back, tail hanging listlessly off the side of the desk, with a rounded stomach from too much food. Tony let out a tiny groan from eating too much, but he was also smiling so Steve considered it a successful experiment. 

# # # # # #

Steve juggled the large box, his house keys and his phone, until he could finally put them all down on his desk beside Tony and his tablet. Tony waved at Steve without looking up from the tablet. 

“Your delivery is here,” Steve said to Tony. 

That got Tony lifting off the tablet and looking up in interest. When he reached out a hand, Steve immediately touched his finger to that little hand. _“Can you open it, please? I’ve been waiting for so long! The delivery system here is as slow as a starfish.”_

Steve had to hide a smile at that, thinking he had never heard that saying before, as he went to the kitchen to get a knife for all the tape. When he came back, Tony was propped up against the box, looking at Steve expectantly. Once Steve started slicing the lids open, Tony laid a hand on Steve’s elbow to keep the communication going. 

“Did you order this using my card?” Steve asked, not angry because he really could spare the cash what with all his back pay. But he did wonder how Tony made the payments.

 _“Yep.”_ Tony was paying avid attention to Steve’s hands, like watching would make the parcel be opened faster. 

“How did you get my card details?” Steve asked, curious. 

Tony shrugged. _“By getting onto your online banking account of course. I needed to get your account details too so I could direct all my payments there.”_

That gave Steve a pause. He stopped what he was doing which resulted in Tony letting out an audible little high pitched squeak of protest. But Steve didn’t continue opening the parcel, instead asking, “Direct your payments? What payments?”

 _“Steve, you mean you didn’t even notice? You really need to pay more attention to your finances! And also your digital security,”_ Tony said, his little face creased in a disapproving frown. 

Okay, it was a good point that his banking account really shouldn’t be that easy for Tony to get into but at the same time, this was _Tony_. Steve had his doubts most humans could do what Tony could pull off in his sleep. 

“What payments?” Steve insisted, knowing by now that half of Tony’s bluster was a misdirection.

Pursing his lips, Tony looked up at him from beneath his lashes, as if gauging whether he should continue. When Steve just looked at him pointedly, Tony relented. _“I don’t have a bank account yet, because I need to crack the security at the U.S. Department of State and Social Security Administration first to get an identity but I’m getting there. So for now, I’m using your account to receive payments. You can use the money in there, I don’t need that much of it.”_

Steve already knew he had a comfortable amount of money saved up, but the way Tony had said it…

“How much money did you put in my account?” Steve asked with no small amount of trepidation. 

_“All of my money,”_ Tony said, widening his eyes in a way that Steve knew right away was him trying to look cute, and damnit, he did look very cute. Steve tried to hold strong against the concentrated amount of adorableness in those big brown eyes set in a small pointed face. 

“And how much is that?” Steve insisted. 

Tony shrugged, waving the hand not touching Steve’s finger airily. _“A few million dollars. Give or take.”_

Steve stared at Tony. “Tony...what. What?” he spluttered. “How do you have a few million dollars? Oh no… _Oh no_ , Tony, did you steal it?”

It was a fair question. Tony had a way with computers and the way he got into Steve’s bank account so easily meant that he likely could do it for other people’s bank accounts too. 

_“As if I would need to steal a few million dollars,”_ Tony said, sounding offended for all the wrong reasons, like a few million dollars was so paltry that thinking Tony had to steal it was just an insult. _“I sold an algorithm and made a few apps of course.”_

“Algorithm? Apps?” Steve asked, feeling at a loss now. 

_“Yes, I offered up a compression algorithm to the highest bidder. It’s not even a really good one, but some people went crazy for it. Then I made a matchmaking app called Matchy Matchy and it’s really quite popular. And the Sea Garbage Party app, you’ve even played that one. You said it was really cute!”_ Tony sounded defensive, like Steve had given his approval by playing a mobile game once and was now renegading on his words. 

Steve frowned and said, “That game was cute, but what does that— wait, you made the Sea Garbage Party game? The puzzle game where all the pictures were little garbage in the sea? It’s the new bestselling game! There was even an article about it…”

Now he was recalling that the article he read was about the mysterious developer taking the world by storm. 

It was Tony. That mysterious developer was Tony.

 _“Yes, I read the article. They called me a genius.”_ Tony preened, flipping his gleaming tail with pride. Then he frowned up at Steve. _“Can you go back to opening the box? You can talk and open at the same time.”_

Steve continued opening the box in a daze, realizing that Tony was even more of a genius than he had initially assumed. He considered that he had several million dollars in his account as he placed the contents of the box on the table: even more tools and electronic items, but all human-sized so he had no idea what use they would be for Tony. There was also a blue machine about seven inches high that Steve couldn’t identify. Tony flopped around on the table in excitement, touching each item and clutching a wrench to his body at one point. 

Holding onto what looked to be some electronic component in one hand, Tony gestured for Steve to bend low to the table and planted a tiny kiss on Steve’s cheek. He did this often now and yet Steve still didn’t stop blushing at the gesture. That made Tony smile up at him before waving him away so he could get back to examining his box of what looked to be random spare parts. 

Steve wandered away and decided that maybe he had better check on his bank account after all. 

# # # # # #

It wasn’t a few million dollars, give or take. 

It was _20 million dollars_. 

# # # # # #

Steve stared at the tiny tools in Tony’s hands. 

“Where did you get a wrench so small?”

The fins on Tony’s tail was spread out over Steve’s wrist so that they could still communicate. _“I made them of course.”_ Tony sounded distracted as he continued fiddling with the joint holding two long rods together. 

“You made them? Using magic?” Steve asked with some surprise. 

Tony pointed to the blue machine sitting at the corner of the desk. _“No, using a 3D printer. It was delivered with the other things and you took it out for me, remember? It will do for now but I plan to use it to make a fabrication unit. I can definitely do better than this 3D printer.”_

So that was what the blue machine was for. It was pretty clever of Tony to get one. 

_“You know, we use something like this in the sea too,”_ Tony said, looking up from his work to wave the tiny wrench around. _“Although we call it something else.”_

“What do you call it?”

Instead of speaking through their minds, Tony made a high pitched squeak that ended with a click, the sharpness of the first note enough to make Steve wince. _“That’s what we call it. But I don’t think you can make that sound in your language.”_

Steve blinked. His language... He didn’t know why he hadn’t ever considered how Tony spoke and read english. It didn’t make sense that an underwater race of people would also speak english. Although there had been a lot going on that first day so Steve had been understandably distracted. 

“How did you learn english?” Steve asked, curious. 

_“By hanging around ships and nearer to shore,”_ Tony said with a shrug, going back to the mechanical parts he was working on. _“Reading was much harder to learn on my own and there were so many gaps I filled in that first day I came here. Us merpeople don’t have a written language so it took me awhile to get used to it.”_

Steve stared at him, boggled. “You taught yourself how to read?” Because he remembered how proficiently Tony had used his phone and devoured information from the first day. “And wait, you don’t have written language?”

 _“Well, of course I taught myself, no one else was interested. And no, we don’t have written language. We store our data and history in seashells, using sound, not in books or through the written word. I rather like the written word though, it’s interesting. A whole new way of communication,”_ Tony mused. 

“Are all merpeople such quick learners like you?” Steve asked in awe, wondering how the Earth wasn’t ruled by a race of tiny merpeople yet. 

_“Nope. I’m a genius,”_ Tony said, flashing Steve an arrogant grin.

“I believe it,” Steve admitted, then added, “To be matched by an oversized ego.”

Tony sniffed, flapping his tail once so that the fins gently slapped Steve’s wrist dismissively. _“It’s not oversized if it’s only a fact.”_

Steve hid a smile at that. 

# # # # # #

Despite the giant aquarium that was finally ready for use in the living room, Tony still seemed to prefer working on the desk, where he was near to Steve. Steve was used to being at his desk and having Tony there with him as well, usually with two little robots zooming about on the wooden surface. 

The little robots were new additions to the various things Tony had scattered around the house. For such a small merman, he was taking over quite a lot of space, not that Steve was complaining. Tony had several miniature machines, and he had even made the two little bots to help him with, well, making more things. 

Tony called the two little bots DUM-E and U, which was a sign that even geniuses had their limits and in Tony’s case, he was very much not a genius at naming things. They were about eight inches tall, and they mostly consisted of wheels and a jointed arm each. Tony seemed to spend just as much time berating them as actually having them help. They seemed to be able to understand Tony’s high pitched squeaks and clicks, arms drooping or perking up accordingly. Steve felt absurdly charmed by the little bots, often feeling a pang of sympathy for DUM-E who seemed to be the one prone to accidents. 

They had developed a routine now, with Tony and Steve working at the desk in the afternoons, with the bots wheeling around the desk carrying out Tony’s orders. Steve would usually take some time to draw all of them, and sometimes he would just gaze upon the little tableau with a fond smile. 

On one such day, Steve finally decided to tackle some paperwork which he had procrastinated on for weeks now. It was tedious and boring work, but the bright sunlight shining through the wide windows by his desk warmed him, and he fell into a steady dull rhythm. 

Steve could only blame the unusual quiet for what happened next. 

Usually his desk was a hive of activity when Tony was there, but that day, it was unusually quiet. There was nothing being manufactured by the miniature fabrication units that took up a quarter of the desk now. Tony wasn’t flopping about in front of his tablet, ordering DUM-E and U about in high pitched whistles and clicks. There wasn’t DUM-E hiding behind Steve’s arm when Tony inevitably scolded him, which usually resulted in Tony waving his little fists even more and then touching Steve’s arm to scold Steve as well for spoiling DUM-E. 

Which was probably why Steve could be excused for...well, forgetting what was usually on his desk. 

He had been sipping on his glass of milk while he worked, and he once more reached for said glass. When he tipped the glass to his mouth, he knew immediately something was wrong but it was too late. 

Little hands touched his mouth and Tony’s voice flooded his mind. **_“Aaaaaah, don’t drink me, Steve!”_ **

Steve immediately pulled the glass away, tipping it upright again. There was the salty tang of seawater on his lips, but he hadn’t drank any. And he certainly hadn’t drank Tony. That would have been impossible, Tony wasn’t small enough to accidentally be drunk down. 

Still, the panic in Tony’s voice left Steve feeling a little shaken and shocked. 

And more than a little bit embarrassed. 

Tony pushed himself up on the edge of his glass, waving a hand at Steve with a thundercloud of a frown on his small face. He was flushed, mouth open in shock and annoyance. Reluctantly, Steve stuck his finger out to receive his scolding. 

He wasn’t disappointed. 

_“You almost drank me, how could you?! Did you forget I was here? How could you forget I was here? How could you almost drink me!”_

Steve winced, rubbing the back of his neck. “I just mixed up the glasses. I wasn’t looking when I reached for my milk.”

 _“So you think I’m interchangeable with a glass of milk?”_ Tony demanded. 

“No, I really don’t think you are. It was an honest mistake,” Steve said. Then realized he forgot the most important part. He looked Tony in the eye with sincere contriteness and embarrassment. “I’m so sorry, Tony. I really am. I’ll make sure it doesn’t happen again.”

The apology seemed to mollify Tony a little. He harrumphed and then said, _“See that you don’t.”_

Then he released Steve’s finger and slipped back into his glass. He sulked there for a good hour, his back turned to Steve so that it was clear to all that Tony was still sulking. DUM-E and U milled about around the glass in confusion, but Tony ignored them too. 

Later, when Tony was over his sulk, he teased Steve mercilessly. It became an ongoing joke. Any time they were arguing or debating anything, Tony would ask, _“What are you going to do? Drink me?”_ which Steve could only huff at in irritation as a response. 

# # # # # #

One day, Steve came home from getting supplies and nearly leapt out of his skin when a smooth voice with a British accent said, “Good afternoon, Sir.”

He looked around, completely confused. To his sharp ears, that didn’t sound like a man speaking from somewhere inside his house. It sounded like a voice that was coming from a set of speakers. But it wasn’t from his television or his radio, and it didn’t sound like something from his phone. 

“Who’s there? What’s going on?” Steve asked warily. 

He edged into the house, moving in the direction of the living room where the voice had came from. A sharp surge of panic went through him as he remembered that Tony was there, working in his aquarium. Steve dashed into the room, abandoning all caution. 

But everything looked normal. His eyes immediately went to Tony who was floating in his aquarium, waving at him jauntily and beaming. DUM-E and U were on the desk as usual, working away at something mechanical. Then Steve noticed the new addition on his desk. It wasn’t anything he had ever seen before. He stared at it, baffled. 

There was a small black disk at the corner of his desk, next to the small fabrication units. Above the black disk floated a glowing blue sphere with blue lines orbiting and criss-crossing around the sphere. When Steve edged closer, he noticed that they were lines of some sort of code that he couldn’t read. 

“Mister Stark has asked that I introduce myself.” The voice was coming from the black disk and the blue sphere pulsed as the voice spoke. “I am J.A.R.V.I.S., an acronym for Just A Rather Very Intelligent System. I have been created by Tony Stark to be in essence, his butler and his communications specialist with the outside world. I can facilitate his work around the house and assist with his business ventures. At this moment, everything you say is being picked up by my voice-to-text program so that Mister Stark can read it on his tablet.”

Steve blinked and looked towards the aquarium. Tony grinned and flashed him a thumbs up, before typing something on his waterproof tablet. 

“Mister Stark says I’m the most advanced Artificial Intelligence on planet earth currently and you should be in awe of his genius,” J.A.R.V.I.S. sounded long-suffering when he said that. Steve realized that Tony was speaking with J.A.R.V.I.S. through the tablet. 

Steve looked between J.A.R.V.I.S. and Tony, smiling. “Wow, Tony. This is really…” He shook his head. “You’re amazing. You’re both amazing.”

“Thank you, Captain Rogers,” J.A.R.V.I.S. said primly, before sighing. “Mister Stark says that he’s amazing and I’m just a product of his amazingness.” The way Tony smirked at that made Steve chuckle. Then J.A.R.V.I.S. continued, “Although I don’t know how amazing Mister Stark can be when he believes it’s logical behavior to go without sleep for 48 hours to work on my code and then, forces himself to stay awake now just so he can see your reaction during our first interaction.”

Tony’s mouth fell open, his little face an expression of outrage at being snarked at by his own creation. That had Steve doubling over in laughter, which apparently made Tony more outraged because J.A.R.V.I.S. said with blandness, “Mister Stark has advised that you should stop laughing at once and that we’re both being very rude to him.”

That only caused Steve to laugh harder.

When Steve finally stopped laughing, he went to the front door to retrieve the supplies he had abandoned on the floor. While he put away their groceries, he let himself process the existence of J.A.R.V.I.S.. Tony’s genius was really unquestionable. Steve had never seen anything as advanced as J.A.R.V.I.S. before, and he had access to quite a lot of tech that regular people didn’t get to see. He could see how J.A.R.V.I.S. would be invaluable to Tony who was now doing business by selling apps and his tech services under an alias. Much of the communication could probably be handed over to J.A.R.V.I.S. now. Those were the parts Tony found most tedious anyway. 

And it also meant Tony could stay in his aquarium for longer hours and communicate with Steve through J.A.R.V.I.S. instead. A part of Steve felt a pang of loss at the idea, knowing that Tony wouldn’t need to be on his desk as often, that he wouldn’t see Tony holding his finger in his two little hands and hear his sharp commentary in his head anymore. 

He knew he was being selfish and unfair. Tony gaining more independence was a good thing. Soon, he might not even need to stay with Steve anymore. With the creation of his bots and with a butler like J.A.R.V.I.S., with the modern world that delivered practically anything you wanted to your doorstep, Steve’s presence in Tony’s life would soon be superfluous. 

Steve tried not to feel like he was about to lose something precious.

His fears were assuaged a little when Tony soon asked to be scooped out of his tank with his glass again and to sit at the desk, holding onto Steve’s finger so he could chatter at him directly. Steve felt warmed at the idea that Tony wasn’t giving up direct communication between them yet. 

But the realization that Tony was learning and adapting in a way that indicated he might not need Steve for long remained a nagging worry at the back of Steve’s mind. 

# # # # # #

“Captain Rogers, Mister Stark has fallen asleep outside of his water again,” J.A.R.V.I.S. announced as Steve was finishing with the curry he was making. It was one of the few dishes he could actually cook with some level of competency, and he knew Tony loved it. 

Steve washed his hands and wiped them off before heading into the living room. Whatever Tony was working on, it seemed to be getting to a crucial state since Tony was getting more and more absorbed in his work, skipping on sleep and spending longer hours at his fabrication units, waving his hands at DUM-E and U. 

He found Tony curled up around a tiny wrench, lying on top of his tablet with his tail a graceful curve trailing onto the desk. Steve was about to pat Tony awake gently when Tony suddenly twitched violently, his head tossing from side to side in a frenzy. His whole body stuttered against the desk, stiffened, his tail arching as his little mouth fell open to emit a piercing whistle that drilled against Steve’s eardrums. Steve winced, forcing himself not to clap his hands against his ears. 

“What’s happening, J.A.R.V.I.S.?” Steve asked in a panic. 

“I believe Mister Stark is having a nightmare,” J.A.R.V.I.S. explained, sounding calm and not at all surprised. It wasn’t the first time then. Since Tony usually slept in his glass or in his aquarium, Steve probably never found out about this. 

Gently, Steve cupped a hand against Tony’s curved back, where he was curling up into a ball of miserable merman. He laid a thumb on Tony’s shoulder and patted him very, very softly. “Tony, Tony, wake up. Tony, you’re safe.” He kept up the soothing words until those small dark lashes fluttered. Then Tony blinked up blearily at Steve. 

_“Steve…”_ Even Tony’s mental voice sounded unsteady, but relieved. 

“Tony, you’re alright. You’re fine,” Steve said, trying to sound reassuring. “You’re a little dried out from staying out of the water too long. Do you want to go into your glass?”

He nudged the glass of seawater closer. When Tony nodded but made no move towards the glass, Steve carefully scooped him up, cradling him for a moment between his hands, taking in Tony’s tired face and limp body in the curve of his palms. Then he gently slipped him into the glass of seawater. The whole time, Tony clutched the little wrench like a security blanket. 

Tony bobbed in the glass of water for a moment, before swishing around and stretching out his tail, his slightly dulled red and gold scales glimmering with deeper color again in the water. Taking a deep breath, Steve tried to relax his muscles and calm his racing heart. He had never felt so helpless before, seeing Tony so agitated but not being able to do anything about it. In that moment, the size difference between them seemed like a terrible barrier. He couldn’t hug Tony, not properly. He couldn’t reassure him without feeling like he could accidentally injure Tony. For the first time, he wished he could shrink to Tony’s size, or that Tony could turn human-sized. 

While Tony was still soaking, Steve went to plate up the food to give Tony some time to himself and also to have something to do with his hands. He let the normalcy of preparation calm his nerves, settle his fidgeting hands. He came back out with a normal human-sized plate of rice and curry, and a tablespoon of curry with tiny bits of meat and rice he had mashed up as much as possible with a fork. Steve rarely ate at his dining table, not finding a point in that even before Tony arrived, since he was mostly alone. He sat at his desk and started eating. After a few minutes, Tony flopped out of his glass and scooted over to his tablespoon of food. Steve laid his left hand down beside his plate so that Tony could put his right hand over Steve’s little finger.

“Are you okay?” Steve asked tentatively. 

Tony shrugged, a motion he had copied from Steve and people on television. _“It was just a nightmare.”_

“Seemed like a bad one,” Steve said with a grimace of empathy. Then he asked tentatively, “Do you want to talk about it?”

But Tony only shrugged again, using his left hand to scoop his food up to his mouth. With the 3D printer or his own fabrication unit, Tony could easily make little utensils to match his size. But merpeople didn’t eat with utensils and Tony didn’t seem to see a good reason for him to start now. 

They ate in companionable silence for a few minutes, both absorbed in their own thoughts about what just happened. 

Finally, Steve asked a little curiously, “What are you working on now? It seems to be getting intense.”

 _“It’s something experimental and it’s proving to be a snagged scale type of issue. I don’t know if it’ll work,”_ Tony admitted, a little bit of his usual liveliness seeping into his mental voice. 

Steve guessed that a ‘snagged scale type of issue’ meant that it was a troublesome piece of work and he decided to try to lighten the mood. “Wow, the great Tony Stark admitting he doesn’t know something.”

Sniffing a little haughtily, Tony said, _“I can hardly believe it myself.”_

Steve had to choke down a laugh at the casual arrogance. But was it arrogant if Tony really was a genius of unusual proportions of intelligence?

 _“I was kidnapped about a year ago, under the orders of my godfather, Obadiah Stane,”_ Tony said all of a sudden, his voice unusually level and calm when Tony was always so animated. _“I was supposed to be killed as part of the deal, but the kidnappers botched the job and only maimed me, left me with damage to my heart. When they realized Obie had paid them pittance for the size of the job and that I might be more useful alive than dead, they tried to get me to make spells for them.”_

He lapsed into silence for a moment. Steve asked quietly, “What happened to the damage to your heart?”

He suspected he knew, what with the glowing circle on Tony’s chest. He had thought maybe all merpeople had it, some kind of evolutionary trait. How wrong he was.

 _“Another prisoner, Yinsen, paid the price to save me. He died so I could live,”_ Tony said, lifting his hand away to tap at the glowing circle set in his chest. Then he put his hand back on Steve’s. _“I shouldn’t be alive, unless it’s for a reason. That’s why I have to make everything I do now count. I have to make sure his sacrifice is worth it.”_

Tony’s dark eyes were almost alight with iron determination, the drive to achieve his objective clear in his voice. Physically, Tony was small, small enough to sit on Steve’s palm. But in that moment, staring up at Steve with blazing conviction, Steve felt like he was looking at a giant who would bend the world with his will.

Steve nodded. “I understand, Tony.”

After a moment, Tony seemed to relax a little, expression softening as he seemed to remember they were meant to be having lunch together. He scooped up food to his mouth. 

Steve asked gently, “What happened to your godfather?”

Tony looked up from the corner of his eyes and said, _“I killed him.”_

The words were said simply, with no apology. But even so, Steve could read the hurt on that small expressive face, hidden as deeply as possible, but not completely buried. It was in the furrow of his brows, the slight downturn of his lips. 

Obie, Tony had called him. Even after everything that had happened, he had used what was obviously a nickname for his godfather. 

Tony wasn’t as distanced from the death as he obviously wished he was. Life was like that. Relationships weren’t so easy to cut off, even when there was deep betrayal involved. 

Steve said quietly, “I’m sorry you had to go through that.”

They held gazes for a moment, and Tony must have read the sincerity of Steve’s understanding. Tony’s gaze dropped before he said, _“Yeah, so am I.”_

# # # # # #

Tony had asked to go for a swim that morning. 

It was unusual because typically, Steve was the one who had to push Tony to come along with him. He was frequently worried that Tony cooped himself up all day indoors, never seeing sunlight that wasn’t filtered through windows. Steve had tried to institute daily morning swims in the sea to which Tony had bargained it down to morning swims every three days. It tended to be less than that because sometimes Tony got stuck into work right after breakfast and refused to go out. 

So Steve was a little surprised when Tony was the one who requested to go down to the beach, when they had gone for a swim two days ago. But still, if Tony wanted some time in the water, then it could only be a good thing. 

Steve took Tony out onto the beach, discreetly carried in a bag, and kicked off his sandals. He waded into the water up to his knees, behaving like he was just admiring the sunrise. Then he bent down and Tony splashed out of the bag into the shallows, as per their usual routine.

Tony’s head bobbed up above the water as he touched Steve’s knee. _“Wait for me, okay?”_

“What do you mean?” Steve asked with a confused frown, but Tony dove into the water. He disappeared swiftly with barely a ripple, only his brilliant crimson tail flipping out into the air before vanishing under the waves. Maybe Steve was just imagining things, but was that tail flip a wave goodbye?

Steve stared after at where Tony had been. For some reason, he felt uncertain, the first stirrings of worry. That was strange because it wasn’t something Tony usually said when he went for his swim.

Chased by a sense of unease, Steve waded out of the water and started his usual routine when Tony came down to the beach with him, keeping his morning jog to the beach. 

Throughout his jog, Steve’s usual calm from pushing his body hard was completely out of his reach. He was plagued by mounting anxiety. What Tony had said sounded ominous for some reason, even though he was asking Steve to wait for him. But why had he needed to ask that? They had an established routine and there was never a time when Steve had to wait for Tony. Steve usually jogged for an hour and went back to the spot in the water right in front of the rockpools where they had first met. Tony would be there, usually complaining about how he had been waiting for Steve. 

For some reason, Steve couldn’t shake the feeling that Tony was going away. Like Tony had to say that, because he didn’t know when he would be coming back. It was ridiculous, but the worry nagged at Steve. He imagined what he would do if he stood in the water but Tony didn’t come back. If he just stood there in the water for the rest of his life, waiting and wondering because he wouldn’t even know what happened to Tony if he never came back. 

He imagined...an empty life, devoid of Tony’s snarky comments and bright smile and endless enthusiasm and shining brilliance. 

Steve knew his worries were absurd, but it didn’t stop him from running faster and faster until he had almost worked himself into a lather by the time he came back to the usual spot near the rockpools at the allotted time. He waded into the water immediately and stood there, breath coming in fast and chest heaving. He held his breath, waiting. 

And waited. 

And waited. 

There was nothing. 

No one.

He squinted into the water, trying to see a small figure with a flash of red and gold. He looked around, worried. They always met up in an hour. Where was Tony? Was he in danger? Stopped from coming back? What could it be? 

Steve stared at the horizon, trying to see something, anything that would give him a clue as to what happened. 

The minutes ticked by and Steve found himself rooted to the spot, anxiety pumping through his veins as he waited and waited. 

Steve realized that it was half an hour past the time they usually met up again. He was stiff with fear, not moving an inch from where he stood. His jaw was clenched against his worries, as he imagined a life empty of Tony’s presence at his desk, empty of Tony’s voice in his head. 

Just empty. 

_“I think you scared all the seagulls away permanently from this beach with how much bad vibes you’re sending out here.”_

Sweet relief swept through him and Steve closed his eyes just for a second as he relished the sound of that voice in his mind. He opened his eyes and looked down, seeing a small bobbing figure, a tiny hand against his shin. It was such a light touch, he hadn’t even felt it. 

Tony gestured imperiously. _“Well? Time to go back.”_

“You’re late,” Steve said through gritted teeth, still feeling the fear sour in the back of his throat. He bent down stiffly, holding the opaque plastic bag in the water so Tony could swim into it. 

Tony held onto his thumb and said, sincere apology in his voice, _“Sorry, Steve. I had to talk to Rhodey and Pepper. It took a little longer than expected.”_

Rhodey and Pepper were Tony’s closest friends and he talked about them on occasion, usually with great fondness. Steve frowned as he straightened up. “Did something happen?”

 _“I just needed to give them an update and they weren’t too happy that I’ve been away for so long. Anyway, let’s go back, the day is wasting,”_ Tony ordered imperiously. 

Steve looked around the beach and saw no one there, the hour still early and this stretch of beach was frequently empty anyway. Lifting the bag, Steve faced out towards the sea with his back to the stretch of pale sand. He looked at Tony’s face, trying to assess his expression. Tony looked a touch remorseful and stressed. But otherwise, he didn’t look upset or like he had been under duress. 

Steve brought the bag closer to his face and decided in an impulsive headlong dive into honesty that he had to ensure Tony knew how important he was to Steve. He said quietly, “Tony, I just wanted you to know that I’m glad to have you in my life. I was worried that you weren’t coming back.”

Tony’s dark eyes widened, before he blinked once, twice. Then he looked away to the side, fidgeting with the lip of the plastic bag as he said with false nonchalance, _“Yeah, same here. I’m glad, and I feel the same as what you said...but about you. And I wouldn’t ever just leave you, Steve, don’t be ridiculous.”_ Tony ended with a slight bluster, obviously deflecting when emotions came into play.

Steve smiled. Yeah, he would take that. 

Then he remembered something and on another impulse, he leaned forward and very, very carefully and lightly touched his lips to the side of Tony’s face. He pulled back quickly, not wanting to disturb Tony overly much. 

Tony was gaping at him, a hand clasped to his cheek. His voice in Steve’s mind was decidedly high and shocked. _“You kissed my face._ **_My whole face_ ** _.”_

“Thank you for coming back,” Steve just said. 

Tony’s face was turning red, a blush that spread across his cheeks and along his neck as well. Suddenly, Steve understood why Tony enjoyed giving him cheek kisses and watching him blush. There was a certain satisfaction to it. Lowering the bag, Steve finally turned around and started wading up towards the beach. Tony had sunk back into the bag, but his hand still clutched Steve’s thumb and he complained the whole way, _“My face. You can’t just go around kissing my whole face. It’s my whole face!”_

Steve would be worried he had offended Tony somehow if Tony didn’t sound so shocked and thrilled at the same time. 

# # # # # # 

Steve had put the unusual morning swim behind him that evening when J.A.R.V.I.S. suddenly called out. 

“Captain Rogers, Mister Stark would like a word.”

Steve had been watching the news in the living room but he turned it off, not finding anything of particular interest beyond some rebuilding going on in New York city. He wandered towards his desk, immediately holding out a finger for Tony to grasp. 

_“Can you pick me up and take me to the couch please?”_

Steve obligingly held out his palm for Tony to hop onto, idly noticing that DUM-E and U were buzzing around two glowing disks on the desk, about five inches in diameter each. He picked up the glass of seawater too. 

“Did you want to watch some TV?” Steve asked as Tony climbed onto his palm. It was unusual for Tony to watch TV at this time of the day, but not impossible. 

_“Let’s sit down, I need to ask you something,”_ Tony prompted. 

Steve felt a little worried. Today was just going very strangely. But he sat down on the couch with Tony, placing the glass of seawater on the coffee table. 

“What did you want to ask me?” Steve queried, trying to remain calm and open. 

Tony fidgeted a little on Steve’s palm before he straightened up as much as possible, leaning on one palm and his tail stretched out to his side. He held onto Steve’s thumb and seemed to steel himself for whatever was coming next. Steve’s apprehension spiked higher. 

_“I need to know…”_ Tony ventured. _“Do you have a micro kink, Steve?”_

Steve blinked slowly, trying to parse that. “Sorry, I don’t understand what that is.”

Tony looked at him with solemn eyes and asked again, _“Do you, as an overly large human being, have a sexual fetish for sentient beings much smaller than you are? Basically, are you only my friend because I’m small enough to sit on your palm and you get off on that idea? I’ve been on some forums that tell me this is a common enough fetish among two-legs.”_

What.

What the hell?

Steve stared at him, jaw just hanging open in shock. 

His mind whirled, spinning as he tried to take in that thought even as his brain seemed to continuously refuse to properly translate what Tony had said. 

“What...what even— Why?” Steve said, rather incoherently. “Why do you— Did I do something that made you—?”

 _“Oh, you didn’t. From your stunned expression, I’m guessing the answer to my question is no?”_ Tony pressed gently. 

“No! It’s— _No_. Really, no. It’s not about your size, Tony. I like you because you’re...you.” In Steve’s shock and confusion, that came out sounding weak and unconvincing for some reason. Steve was ready to write off the complete day with how badly he was messing this up. 

_“Okay, good, good. Not that there’s anything wrong with a micro kink, if you did have one. It sounds like a logical kink to have really,”_ Tony rambled, and Steve’s imagination was conjuring images that was making him go red in the face. Then Tony continued, _“But if it’s not my size, then at least it won’t be so awkward when I do this.”_

Steve was still struggling not to combust with embarrassment as he watched Tony reached up and touch the glowing disc in his chest. Tony closed his eyes, a tiny furrow appearing on his brow. That was when Steve realized that it was usually a glowing circle on Tony’s chest, not an entire glowing disc. When did the disc replace the circle?

The light on Tony’s chest flared sharply and spilled outwards, sudden enough that Steve found he couldn’t see, blinded by the abrupt white blue light that filled the room. He shaded his eyes with his arm but it was too late. He was still blinking away little starbursts of light when he slowly tried to look around. 

Then he stared. 

Sitting on the couch was Tony. Except Tony wasn’t small enough to fit on Steve’s hand anymore. 

Tony was full human-sized, except maybe even taller if he could somehow stand, because he still had his merman’s tail. The tail was very thick and long, about two feet longer than Steve’s own legs. The tail’s red scales shimmered with a rich gold lustre under the indoor lighting and the tail fins draped over the fallen coffee table that had been knocked over when Tony changed in size. Steve’s eyes traced up Tony’s body, up and past where scales turned to soft pale skin. Tony’s body was leanly muscled, something he hadn’t noticed before, with broad shoulders and a firm chest tapering down to a slimmer waist. His arms looked strong, his fingers long and graceful. 

And Tony’s face… It was at once familiar and foreign. Steve had drawn that face countless of times, the little lashes against pale cheeks, that mischievous smile. But it was somehow different when human-sized and seen from a few feet away, rather than a small face that Steve had to peer at usually from afar. 

How had Steve never noticed that Tony was the most gorgeous person Steve had ever met before? His deep brown eyes were lined with thick dark lashes, a razor sharp goatee styled to perfection around soft pink lips. Without product, his hair was fluffed up and messy, but if it had been styled, Steve could easily picture Tony as one of those handsome debonairs, even better looking than Cary Grant, with the kind of timeless handsomeness that stole Steve’s breath away.

Steve realized that his hand was wedged under Tony’s tail, probably trapped there when the size change suddenly happened and Tony would have abruptly outgrown the hand he had been sitting on less than a minute ago. Unconsciously, Steve’s fingers twitched, feeling with shock the smooth ridges of large warm scales against his skin.

“Tony?” Steve said, his voice embarrassingly high. 

Tony tipped to the side a little and pulled Steve’s hand out from between his tail and the couch cushion. He smiled and held Steve’s hand. _“Hello, handsome. You look very different when seen like this, instead of when you were this big giant. We’ll talk about that a little more but I need you to do something urgent for me.”_

“How did you— How?” Steve asked as his mind swam with questions. 

_“Not to cause you any panic, but I’ll have a heart attack in about one minute, so I need you to focus,”_ Tony said calmly, even as his free hand tapped the disc on his chest. 

Which wasn’t glowing anymore. 

Steve jerked and then asked with urgency, “What do you need me to do?”

 _“Go to the desk and pick up the two glowing discs there please. I kind of forgot about them,”_ Tony instructed. 

Steve lurched into motion, grabbing the two discs and practically throwing himself back towards the couch, his arms outstretched. Calmly, Tony reached up and removed the dull disc in his chest. 

The disc was about an inch thick but when it came out from Tony’s chest, there was no hole or indentation where the disc should have sat. It must have been magic. Steve stared with alarm at the inert blue circle on Tony’s chest that was also dull and no longer glowing. Without any hesitation, Tony picked up one of the discs from Steve’s hand and inserted it into his chest. Somehow, it pressed _into_ his chest and lay flat against his skin, settled into place. 

“What happened, Tony? How did you change your size? And why did your chest mechanism go out?” Steve asked with no small amount of anxiety. 

Tony lay a hand on Steve’s again. _“I’m calling the chest mechanism an arc reactor. Sounds cool, right? As for how I turned big and why the arc reactor died, they are both tied to the same cause. Originally, what I had embedded in my chest was just spellwork that kept my heart going. I’ve since developed a technological solution blended with magic.”_

That sounded...extraordinary. 

Steve asked with awe, “So that’s what you’ve been working on all this time? An arc reactor, a combination of tech with magic?”

 _“Yes, mostly that, but some time was also spent on learning about other kinds of technology Earth has and all your confusing social norms,”_ Tony explained, before continuing, _“Anyway, magic requires a sacrifice to work. A spell for a price. Well, the arc reactor can power a skyscraper for 100 years before it’s drained. When I changed sizes, I fed the spell with the arc reactor’s power. 100 years of energy in exchange for my size change. That seems reasonable.”_

Steve looked at him, looked down his body in sheer awe. Tony had done it. He had created a power source that could power his size changes without require blood and flesh sacrifices.

Then a thought struck Steve. In a panic, he said, “Tony, you can’t fit in a glass anymore.”

Tony raised an eyebrow, an expression he learned from TV. _“Yes, good observation.”_

Steve rolled his eyes at the patronizing comment. “I meant that you’ll dry out if you stay out for too long and we can’t just pop you into a glass of seawater or the aquarium. I’ll go fill the bathtub now with seawater. You won’t be able to fit entirely but surely you’ll fit enough to soak your scales.”

The only reason why Steve didn’t jump straight to doing that was Tony’s restraining hand on his wrist. Tony leaned in, looking into Steve’s eyes. _“It’s not urgent, I’m nowhere close to drying out. And I’ve got another important question to ask you.”_

After the sudden revelation that Tony needed something from the desk otherwise he would have a heart attack, Steve was wary of anymore important requests or questions. “What is it?”

Tony looked him in the eye and asked earnestly, _“Do you have a merman or scales fetish?”_

“Why do you keep asking these kind of questions?” Steve cried out in frustration. 

_“I didn’t think you really had a micro kink but a merman or scales fetish… Well, I have a very shapely tail in gorgeous eye-catching colors, and you haven’t encountered other merpeople before. It makes sense that you might be dazzled by my scales or might have a fetish for it, who wouldn’t after all?”_ Tony pointed out, gesturing at his own body, from his collarbone to the fins on his tail. _“So I just wanted to check if you liked me specifically because I have a beautiful tail.”_

Staring at Tony’s earnest querying face, Steve felt like he was losing his mind. “No, Tony. No, it’s not because of your scales or your tail,” he said with forced calm. 

_“Oh, good!”_ Tony said with quite a lot of cheer. 

Steve should have expected what came next considering the events that had transpired, but he still wasn’t ready for the flash of bright light right as Tony tapped at the arc reactor in his chest. Steve nearly fell off the couch and he had to rapidly blink for a few seconds before his vision cleared. 

And before him...was Tony. 

Tony in human-size, sitting on the couch...with _legs_. 

Steve gawked at Tony, barely noticing as Tony switched out the now dull arc reactor in his chest for the second still glowing arc reactor. The bright red and gold tail was gone, and what was left behind were regular legs that stretched out, with thick muscular thighs and strangely shapely calves, complete with a soft penis resting against one thigh. 

“Oh my god,” Steve said, eyes snapping up. “You have _legs_. And you’re naked.”

Tony said, “I’m always naked, that’s not new.” Then he gasped. 

Steve gasped too. 

Because that hadn’t been said inside Steve’s mind. That had been spoken outloud. Tony’s voice sounded exactly the same as when spoken in Steve’s head; a smooth, slightly low voice, with a sarcastic lilt to it. The words were a little awkwardly pronounced, a little rushed, which was to be expected because…

...because this was the first time Tony had spoken aloud. 

“I can talk,” Tony said, as if testing the words. Then he looked down at his legs. “And I have legs! Oh sweet anemones, I can walk and talk!”

He leapt to his feet with his arms up in the air. 

And promptly toppled over. 

Steve caught him, having leapt to his feet with more success when he noticed Tony’s imbalance. His arms wrapped around Tony’s upper torso, and Tony’s hands were pressed to Steve’s chest. Looking down, Steve realized that Tony was a few inches shorter than Steve now, which was an interesting thought to have considering that Tony was only a few inches high in totality a few minutes ago. 

Tony looked up through thick dark lashes, probably not realizing what a potent gaze he had. “Guess I need to get used to balance first. Talking seems a lot easier than walking.”

Suddenly, Steve was acutely aware that he had an armful of naked Tony, whom he had just realized was scorchingly attractive. 

“I, uh, I’ll get you some clothes to wear,” Steve said, sounding more breathless than he would prefer. 

Tony frowned. “Why? I never had to wear clothes before. Although it’s interesting to have a penis hanging outside instead of protected within my scales.”

The moment the word ‘penis’ passed through those pink lips, Steve deposited Tony as gently and quickly as humanly possible onto the couch and dashed for his bedroom. He heard Tony calling after him, which was a novelty to be able to communicate without skin contact, but he kept going until he reached his closet. He spent a solid five minutes with his head inside his closet, allowing time for his heart to stop racing and his cheeks to stop burning. 

It took a surprising amount of effort to get Tony into clothing. For one thing, there was a lot of complaining from Tony while Steve averted his eyes. Then there was the fact that Tony was still wobbly on his feet and needed help to get dressed. Steve was flushed to his hairline and had been staring mainly at the floor the whole time he held Tony up, helped him manoeuvre his legs, pulled on his clothes…

It was an ordeal. The most tempting, sweetest ordeal ever. 

By the time they were done, Tony was standing on his own two feet, a little unsteadily, his hands clasping Steve’s forearms. 

“I suppose I have to learn to blend in with other two-legs,” Tony said with a huff, like blending in was completely beneath him but he would try. 

“That would be a good idea,” Steve said inanely, trying not to stare at Tony’s face, at the quirk of his lips. But then his eyes shifted to the overly large shirt Tony was wearing — he was wearing _Steve’s_ clothing — and the collar was wide enough on him to show the tantalising glimpse of collarbones and one shapely shoulder. 

“Steve,” Tony murmured. 

Steve’s eyes snapped back up to see Tony’s dark brown eyes, staring right at him. Oh god, he had been caught staring.

He was about to stammer out an apology, feeling overheated from all the blushing he was doing today, when Tony’s face drew closer and closer, and suddenly…

Soft lips pressed against his. It wasn’t a light peck, there and gone again. This was a _kiss_. Tony pressed forward with intent, lips lingered against Steve’s, and the feel of Tony’s mouth against his own, soft facial hair against his skin, sent a bolt of heat through him that coalesced in the pit of his stomach. A shiver thrummed through his blood, shuddered through his bones. 

Tony was _kissing_ him. 

Then Tony drew back and Steve’s eyes fluttered open, just in time to see a lithe pink tongue sweep out along Tony’s lower lip, as if chasing Steve’s taste. 

The sight was so hot, it was almost enough to sear Steve’s vision away. 

But Steve had to check, because there were so many cultural differences between them. He had to be sure. 

So he asked, a little hesitant, “Is that...a thank you kiss?”

Tony’s lips curled up in an amused smile. “That was a ‘I like you very much’ kiss.” Then he frowned slightly. “Was that not clear? Did I do it wrong? There’s only so much I can learn from TV and books without practical application. Merpeople don’t kiss when we’re romantically interested in someone, you know? We do tail-twining, it’s very sexy. I wasn’t sure if I should have used tongue right a—”

“No, you did fine,” Steve interrupted, not wanting Tony to feel even a moment of doubt about this and also, not sure if he could survive hearing Tony talk about using _tongue_. “You did...more than fine.”

The frown faded and Tony looked smug again. “I’ve always been a fast learner.”

Steve cleared his throat, aware that his hands were rubbing up and down Tony’s arms without his instruction but not intending to stop. “If it wasn’t obvious, I like you too. Very much.”

Tony’s smug smile turned into a happy and bright one, the joy of it familiar and never failed to make Steve’s heart squeeze with reciprocal happiness. Steve realized that maybe he hadn’t realized how attractive Tony was before his transformation, but there had definitely been something more going on between them even before this moment. 

Blinking slowly, Tony gave Steve a sly look. “Would you care to help me apply the theory to more practice? There’s a lot I’ve read which I’ve imagined doing with you.”

Tony was definitely going to be the death of him, Steve thought, as he flushed and Tony giggled.

But what a way to go. 

“I would be honored,” Steve said with a smile of his own, drawing a beaming Tony close for another kiss, this one slower, with a tease of tongue and parted lips which had Tony groaning and clutching at his shoulders.

After all, Steve had to keep Tony on his toes too. 

# # # # # #

They spent the afternoon making out like teenagers, before ordering dinner in. While they sat at the couch waiting for their pizza delivery, Steve noticed with some amusement that Tony held onto his wrist when they talked, even though they didn’t need skin contact to communicate anymore. It seemed like old habits die hard and Steve enjoyed the physical touch anyway. He knew with time, Tony would probably stop doing this, especially when he had both hands deep in the guts of some machine and realized he could talk to Steve without having to stop what he was doing.

Steve would miss the constant contact, but he thought it was a fair exchange to have Tony here, in full size, able to talk to him whenever he wanted. 

“So you can change back to your merman form as long as you sacrifice an arc reactor?” Steve asked, curious. 

“Yep.” Tony nodded. “But I’m not going to do that for awhile. It’s why I went back to the sea this morning to talk to Pepper and Rhodey. I wanted to tell them that I likely wasn’t coming back for awhile. They made me promise to make the spell and tech work for them eventually so that they can come visit me up here too.”

Steve furrowed, catching the word Tony had used. “You _likely_ weren’t going back for awhile? Wait, you weren’t sure it would work.”

Tony grimaced and then shrugged, caught out. “An amalgamation of magic and tech is always tricky. There are risks.”

“You shouldn’t have tried it unless you were more sure,” Steve said, horrified at the idea that it could have all gone horribly wrong. 

“I was 78% sure!” Tony protested. “Sure enough that I’m willing to try it on DUM-E and U to make them bigger, once I have a couple arc reactors ready. I’m going to be working on a much larger scale from here on, so I need them bigger too.”

Tony could probably easily rebuild other larger, helper bots, but Steve already knew he wouldn’t. Once Tony was attached, he didn’t let go easily. He even had a favorite wrench he slept with. 

Steve knew Tony was deflecting, but he decided to let it go. 78% confidence was higher than some of the risks Steve had taken in his life. 

Tony was tapping a rhythmic beat against Steve’s wrist, not meeting his gaze for the moment. Steve asked with some worry, “Is there something wrong?”

Shrugging, Tony said, “I just wanted to check… I made myself the same size and shape as most two-legs so that we would be on the same playing field together, but also...I have a mission to complete, Steve.”

“I know, Tony. I remember what you said about Yinsen. You want to make your life count, you want to do something,” Steve said, remembering Tony’s words. 

Tony’s stiff posture visibly softened as he relaxed. “Thank you.”

“So what’s your mission?” Steve asked. 

“I’m going to use technology to clean the ocean. It’s full of two-legs’ garbage nowadays, too much for magic to deal with, not without a great cost. But tech? Tech is perfect for it. All we need is advanced machinery and money. And I can get both.”

Tony paused, glancing towards his tablet that he had placed on the arm of the couch. He continued, “I’ve got a second mission, which based on the blinking lights on my tablet, is going to have relevance to your visitor.”

Steve frowned. “What visitor?”

Loud, impatient knocking started against the front door. Tony only smiled and shrugged when Steve looked at him questioningly. So Steve sighed and went to answer the door. At least Tony didn’t look perturbed so it couldn’t be that bad. Maybe Tony was just kidding around and that was their pizza arriving. 

When Steve opened the door, he found Nick Fury on his doorstep, holding two boxes of pizza.

Damnit, Tony. A little heads-up would have been nice. 

“Pizza delivery,” Fury said, deadpan. 

Steve had a moment of hesitation, knowing he had Tony on the couch, Fury on his doorstep, and both of his previously separate worlds were going to collide, and collide _hard_. He didn’t know who would survive this collision. 

“I’m very worried, Captain, and the longer I stand out here, the more worried I get. Along with the rest of S.H.I.E.L.D.,” Fury said in a biting tone. The message was delivered loud and clear. He had S.H.I.E.L.D. agents out there, ready to move in. Something had pinged their radar hard enough to have them worried. 

Steve sighed and stepped aside. 

When Fury walked past him, he looked around with a soldier’s care, a spy’s gaze, alert for any hidden dangers. 

“What are you worried about, Nick?” Steve asked, trying to ease the tension. “I’m on vacation right now and I’ve just got a friend visiting. He’s a civilian.”

“A civilian,” Fury snorted as he stepped into the living room, as casually as he could while scanning the room.

He took in the sight of Tony on the couch and his movements slowed with extra caution. With a lazy smile, Tony lifted a hand and wriggled his fingers in greeting. It wouldn’t be hard for Fury to guess what they had been doing recently with their mussed up hair and wrinkled outfits, especially with Tony obviously wearing Steve’s clothing. But Steve couldn’t care less what Fury assumed, as long as he didn’t know Tony’s actual origins. Steve had no idea what S.H.I.E.L.D. would do if they found out about a whole race of small magic-wielding merpeople and he wondered how they were going to keep Tony’s actual identity under wraps from an organization like S.H.I.E.L.D.. 

Then, Tony spoke up, “They’re worried about the two massive power surges they detected here. They probably rushed over expecting to find this little seaside town nothing but a smoking crater, with your holiday home at the center of the blast radius.”

Right, if S.H.I.E.L.D. had detected the arc reactors when they were sacrificed for the spells, then that would be very difficult to explain away. 

Fury stopped at the side of the couch, not moving any closer. Surreally, he was still holding the two pizza boxes. “Who the hell are you?”

“I’m Tony Stark, mysterious millionaire tech genius, founder of the brand new clean energy company Stark Industries but for some reason, I’m more well known as the creator of the app Matchy Matchy and the game Sea Garbage Party. I just did a phone interview with the New Yorker, so if you want to disappear me, it won’t be that easy,” Tony said with a casual wave of his hand. 

Disappear him? What the hell?

Steve was going to tell Tony that would never happen, when Fury said, “You would be surprised what S.H.I.E.L.D. can do with sufficient motivation.”

“Nobody is disappearing anybody,” Steve said sharply, moving towards the couch so he stood between the two people glowering at each other. “Fury, why don’t you put the pizzas down and have a seat please.”

Fury and Tony continued staring at each other for a moment longer, before they both nodded reluctantly at each other. 

Fury sat down on the other end of the couch, sliding the pizza boxes onto the coffee table, to reveal that he had been holding two guns under the boxes. When Steve glared at them, Fury unrepentantly slid them into their shoulder holsters beneath his jacket. Shrugging, Tony turned his hand up to show a little black rod, small enough to be hidden in his palm. He slipped it into his pocket. 

“What is that?” Nick asked, reluctantly curious. 

Tony shrugged. “A taser that will take down a full grown adult.”

Fury blinked at him slowly. “In that little thing?”

“Genius, remember?” Tony said with a sharp grin. 

Deciding to play human shield, Steve sat down on the couch between the two of them. 

“What was the two power surges about?” Fury asked. The interrogation had started in earnest it seemed. 

“It’s how I make a grand entrance to an organization like S.H.I.E.L.D.,” Tony replied carelessly, without explaining anything whatsoever. 

Fury’s expression was unimpressed, clearly noticing the deflection. “Where are you from? Your identity is falsified and didn’t exist until a couple weeks ago.”

“I’m from around here but I want to keep my family and friends safe, so I needed a new identity.”

“Why did you befriend Steve?”

“Because he’s a good man and I thought I could trust him.”

“Not because of anything else?”

“Oh, I only found out about his Captain America identity after we became friends. That was interesting but it wasn’t why I approached him,” Tony said airily. 

Steve startled, looking at Tony with wide eyes. Fury glanced between them and threw up his hands before saying to Steve with a heavy amount of wryness, “At least you didn’t tell him all your secrets on your own.”

“When did you find out?” Steve asked Tony, unsure how he felt about this new development.

“A few days after we met. It wasn’t hard to piece together,” Tony said, frowning a little as he looked at Steve, looking worried for the first time since Fury walked in. “The alien invasion in New York was all over the news and there was a lot of coverage on the rag tag group of superheroes on the ground, including Captain America.” That was an oblique reminder to Steve that Tony might not have been spending time on dry land at that point, but he had done a lot of reading later on once he figured out how to navigate the internet. 

Tony continued. “The timing fit. You turned up here on vacation after the alien invasion, clearly in need of rest after a stressful ordeal. You forget your strength and speed sometimes. If the beach wasn’t so deserted most days, I’m sure everyone there would know you’re Captain America, with the speed and stamina you show when you jog. And your strong jawline and lovely mouth and pretty blue eyes are all quite distinctive, they’re hard not to recognize even from blurry mid-battle photos.”

Fury’s eyebrows went up at that last bit and Steve had to struggle not to blush. He had no doubts Fury was recording this conversation and that Nat would get hold of it at some point. He would never hear the end of this from her. 

“So you knew all along,” Steve said with some uncertainty. 

On one hand, why didn’t Tony ever say anything to him? On the other hand, Steve never said anything either. He knew why he hadn’t, had been enjoying the feeling of someone who didn’t treat him like Captain America rather than just regular Steve Rogers. He didn’t think Tony would treat him any differently if Steve had told him he was a supersoldier from a science experiment in the 40s and had been frozen in the ice for decades, that Tony was probably learning about the modern world at greater speed than Steve had been. But at the same time, he had been reluctant to broach the subject, to change their status quo. 

Well...he didn’t have to, it turned out. Tony had figured it out on his own and he hadn’t treated Steve any differently anyway. 

“I know it’s a secret, I won’t tell anyone,” Tony said in earnest, still looking worried at Steve’s reaction. 

Taking a deep breath, Steve forced the tension out of his body. Tony had entrusted bigger secrets than this with him and he hadn’t behaved any differently around Steve. With some wryness, he realized that he should have expected Tony’s genius to have figured things out early on. 

He reached out and placed his hand palm up on Tony’s thigh. Immediately, Tony put his hand down on Steve’s, linking their fingers together. Fury’s eyebrows looked like they wanted to levitate off his forehead, but Steve only stared at him defiantly. 

Then Fury rolled his eyes. “I don’t care about what hanky panky you get up to on your down time, Cap.”

“Good,” Steve said, a little stiff. “Because it’s none of your business.”

Fury turned his gaze back at Tony. “To get back on topic, you expect us to believe that you’ve been living around here all this time and you just approached Captain America because you noticed he was a good guy. Then you created a brand new identity, one so airtight S.H.I.E.L.D. can’t even expose it, in a way where we can’t find a single trace of you from prior to your appearance in Captain America’s life?”

“Well, I mean, I also approached him because of his aforementioned lovely mouth and pretty blue eyes. And you should see how he runs on the beach. All those muscles and glistening sweaty body, you expect me not to approach him?” Tony asked, grinning as he enjoyed how Steve was blushing. 

Fury snorted, a sound of impatience. “Mister Stark, what exactly is your motive here?”

“I want to make the world a better place,” Tony said with a smile, before his eyes brightened with mischief. “And I want to talk to you about the Avengers initiative.”

# # # # # #

_Six Months Later..._

Steve looked out over the expanse of blue sea, wondering if there were any D.E.R.P. units in this area. The Disposing Errant Rubbish Pronto units, a name that Tony refused to budge on, were little machines Tony had created to gather the trash in the ocean and deposit them into a floating garbage heap to be collected later. The world had been taken by a storm with Tony’s clean energy company and his aim to clean up the ocean within the decade. 

But thoughts on D.E.R.P. weren’t enough to occupy Steve’s mind and soon, his gaze drifted up to the land mass still miles away, just a small blotch against the blue seas.

He wondered if Bruce would appreciate their arrival. 

“Don’t worry, he’ll like me.”

Steve turned away from the window, straightening up from where he had been leaning against the quinjet’s inner hull wall and smiled. “That wasn’t what I was worried about.”

“Good, I would have been offended if you were worried about that,” Tony said, clomping up to him in his red and gold armor, faceplate lifted so he could talk to Steve. 

He leaned in and Steve tilted his face up for a kiss on the cheek, both angling their heads automatically so that Steve wouldn’t be smacked by the faceplate. They had learned through trial and error on this. Steve smiled as he felt soft lips and facial hair against his cheek, remembering a time when a much smaller, feather light kiss had been bestowed on his cheek. How things had changed. His life had been a whirlwind ever since Tony arrived and he didn’t think it was going to change any time soon. 

He was very thankful for that.

“Do you think he’ll agree to come back?” Steve asked, hopeful. 

“Our communication has been positive so far. And I’m tempting him with a state of the art lab,” Tony said with a grin. “He might have had his reservations before about joining the Avengers considering the ties to S.H.I.E.L.D.—”

“That’s putting it mildly,” Steve murmured. 

During the chitauri invasion, the World Security Council — which S.H.I.E.L.D. reported to — had tried to nuke New York in a move of extreme stupidity. Bruce in his Hulk form had grabbed hold of the nuclear missile, jumped to the highest building, and jumped through the portal with the nuke. He had fallen back out eventually, crashing on top of a building. But when they had went looking for him, all they found was a building with its top five stories destroyed by heavy impact, and the Hulk was nowhere to be found. 

Thor had taken Loki and the Tesseract back to Asgard shortly after. Clint had been benched as they had tried to figure out if the mind-control by Loki had been completely removed, while Natasha had been sent almost immediately on an undercover mission where she was completely out of reach from everyone. Steve had withdrawn to an isolated seaside town to lick his metaphorical wounds and try to handle his feelings of loneliness after being woken up almost 70 years into the future, discovering all his friends were gone, being thrown head first into a battle with _aliens_ , and then seeing his temporary team disbanded almost immediately. 

The Avengers initiative had been over within the space of one battle. 

Except Thor was back from Asgard now and Tony had managed to track Bruce down, exchanging text messages for the last month until Bruce agreed to a visit. Tony said he had an interesting idea on medical scans that had Bruce’s attention. And he was also enticing Bruce with special stretchy pants tech that would ensure the Hulk’s modesty wasn’t threatened every time he transformed. According to Tony, both topics seemed of equal interest to Bruce. 

With Tony’s arrival, the Avengers as a team didn’t sound so impossible anymore. 

When Steve had asked Tony once why he wanted to be in the Avengers when he could instead focus on his clean energy plans and on cleaning the ocean, Tony had looked offended and said, “One, I can multitask, thank you very much. Two, I live on this Earth too, you know. If there’s going to be alien threats that regular people can’t handle, then I want to help.”

Wanting to help was a need that Steve could easily understand as well.

So Tony had created Iron Man, a red and gold gleaming armor that could _fly_ and blast repulsors and basically, defy the laws of physics. Iron Man was amazing, just as amazing as Tony was. 

The Avengers was a team now for more than three months. But it was a team that felt incomplete...

“Do not worry, Captain. I’m sure Bruce will be interested in joining us now that Stark is funding the Avengers, with no involvement from S.H.I.E.L.D.,” Thor said from the other bench in the quinjet.

“Even if he wasn’t, Tony would just bug him until he did,” Clint called out from the co-pilot’s seat up front.

From where she was flying the quinjet, Nat agreed. “Or trick him into it.”

“They’re bullying me, Steve, stand up for me,” Tony complained, slinging a metal arm around Steve’s shoulders and leaning the side of his helmet against Steve’s cheek.

Steve turned and gave the cold metal a kiss, knowing Tony’s sensors would pick up on it. “Then you would complain that I was being overprotective of you.”

“You know me well,” Tony agreed with a grin. 

Clint sighed. “Keep your flirting down, come on.”

“I’ll flirt if I want to,” Tony shot back, before turning to Steve, examining his face. “Look, you’re too worried over what’s essentially a friendly meet up. How about we fly ahead instead?”

Steve looked at him, confused. “We are flying right now.”

Tony smirked. “I mean, fly with me, with Iron Man. We’ll get there faster than the quinjet.”

That was an appealing idea. “Yeah, let’s do that.”

“Adrenaline junkies,” Nat commented, but she sounded fond. 

When they leapt out the back of the quinjet, both of them whooping with delight as Steve’s arm wrapped tight around Iron Man’s shoulders, Steve thought that there was never going to be a time when he would turn this down. He loved how they soared and spun through the air with Tony’s voice in his ears and Tony’s body encased in metal pressed close to his as they flew together. He would never give this up, the way the wind almost hurt against his skin, the way his heart pounded as they plummeted down before swooping upwards in a graceful arch, the way he could feel Tony’s strength and enthusiasm right by his side. 

He thought that one day, he wanted to experience this in the ocean, when Tony figured out a way to shrink Steve down and give him a little tail of his own. Then they would dive through the waves and swim through the sea together, skin against skin, scales against scales. 

For now, they had the endless blue skies ahead of them.

# # # # # #

_Not Yet The End, Because Another Six Months Later..._

Steve stood by the rockpools, staring out into the sea. It was barely dawn, the sky mostly dark with the sun just peeking over the horizon. 

He couldn’t imagine how life would be like now if Tony hadn’t so unceremoniously inserted himself into Steve’s gray existence, right on this very same beach more than a year ago. And now, Tony was taking him on a different adventure. It would only be for a couple weeks, the longest the world could spare the two of them, but Steve already knew it would be an unforgettable two weeks. 

“It’s so early,” Tony moaned, splashing up to his side before leaning his head on Steve’s shoulder. 

Steve wrapped an arm around Tony’s waist and pulled him snugly close to him. “It’s so that no one sees what happens. You agreed on that yesterday.”

“Past Tony is an idiot,” Tony grumbled.

“No, he’s not,” Steve said with a laugh, reaching up to brush Tony’s messy hair down before kissing him on his temple. 

Tony sighed and pulled away a little. He looked down at the two arc reactors Steve was wearing on a chain around his neck. They were large and a little unwieldy on a chain, but they would serve their purpose. 

“Alright, let’s go then,” Tony said, covering his mouth when he broke into another yawn. 

Hand in hand, they waded out further into the water, until they finally had to let go and start swimming instead. When they had swam far enough that they had to tread water, they turned to face each other. Tony was bobbing a little frantically in the water, having never gotten used to swimming without his tail. 

“You have your spare arc reactors?” Steve asked. 

Tony nodded, lifting the normal-sized arc reactor and the tiny arc reactor he had on a chain around his neck. “I’ll hold onto it when I shift, I know how this should be done.”

“Alright, let’s do this then,” Steve said with excitement thrumming through his veins. 

Grinning, Tony said, “Take a deep breath.”

As Steve drew in his breath, Tony reached out and touched both the arc reactors hanging around Steve’s neck. 

The world contracted around Steve. It pulled in and squeezed, shoved him down and in until he couldn’t breathe and it was just too much, there was just too much bearing down on him…

Then he gasped. 

Steve’s eyes snapped open as he looked around in confusion. 

He was underwater, quite a distance from the surface, and when he looked around, it was mainly just blue water all around him. Did it work? Did he—

Steve looked down and gasped again, except he realized that if he gasped, he would swallow seawater. 

But he wasn’t swallowing seawater. He was just...breathing as if this was normal. And he didn’t have legs anymore. Instead, he had a beautiful vibrant blue tail with silver fins. Steve touched his hips gingerly, marvelling at the feel of scales beneath fingers. He took a few deep breaths, enjoying how he was breathing through the water with no trouble at all. 

Steve felt a light touch against his shoulder and he turned to see Tony, back in his merman form with his brilliant red and gold scales. He looked down and was glad to see the glowing arc reactor was in place in Tony’s chest to replace the one sacrificed for the spell. 

_“Tony, it worked!”_ Then Steve’s eyes widened in surprise as he realized that he wasn’t _speaking_ , at least not by the standards of most people on land. He was speaking like how Tony used to, through the mind. 

Tony grinned. _“It did. How do you like your new tail and fins?”_

Swimming a circle around Tony, Steve tried to get used to propelling himself with his tail and clutched Tony’s shoulder to pull himself to a stop. _“It’s amazing.”_

 _“They’re gorgeous,”_ Tony said with quiet wonder in his voice, running a hand over Steve’s scales on his hip. Steve shivered, surprised at how sensitive his scales were and how he perceived the touch differently, feeling a tingling sensation even before Tony’s hand came in contact with his scales.

 _“Are you going to teach me how to twine tails?”_ Steve asked, blinking slowly. 

Tony’s hand on Steve’s hip squeezed reflexively. _“I, uh, yes, if you want?”_

Steve grinned, darted in for a kiss against Tony’s cheek and then dived deeper down, swimming away. _“You can teach me later. Come on, Tony, show me your life under the waves.”_

 _“You’re a terrible tease!”_ But Tony was laughing in delight as he called out, propelling himself forward with a big push from his tail to catch up to Steve easily. _“I know you’re excited, Steve, but don’t leave me behind. The ocean can be a dangerous place.”_

 _“I would never leave you behind,”_ Steve replied, smiling to see Tony by his side again. _“Wherever we go, we go together.”_

_“You’re such a sap,”_ Tony murmured. But he clasped Steve’s hand and tugged him deeper into the welcoming currents, into the endless blue seas ahead of them.

**THE END**

**Author's Note:**

> I hope you all enjoyed this! Sorry for writing essentially one ending, and then continuing the story, lol. I couldn’t resist. I wanted to have the Avengers and the sea in my endings.
> 
> Credit goes to Captain Handsome, who started this all by drawing a very cute merman Tony and then telling me that the drawing was to scale, and merman Tony is tiny, which resulted in a lot of back and forth cracky-cute ideas. I’m sure you recognise most of these ideas, Captain Handsome!
> 
> Edit to add: Please go feast your eyes on the cutest fanart ever omg, [Little MerTony by Captain Handsome](https://this-is-captain-handsome.tumblr.com/post/626359864294277120/doodles-of-little-literally-mermaid-tony-that)!


End file.
